[Aerobiological study in Lima, Perú. ¿Tipuana-Tipu, perhaps a new allergen?]

Objective: To report the Tipuana tipu pollen as a new allergen capable of triggering allergic symptoms.

Methods: The pollen counts were made according to standardized technique with a Burkard seven days following the European Aerobiology Society´s Network Group recommendations.1 The trap was installed on the roof of Clinica SANNA, El Golf, San Isidro, which is 20 m high, 12°5'54"S 77°3'6"W in the west-south of the Lima urban area. The sampling period was performed from September 2020 to October 2021. Collection of Tipuana tipu pollens and Preparation of Tipuana tipu pollen extracts 1:20 w/v was done using a previously described method.2 We carried out systematic skin prick testing with Tipuana tipu pollen extract and other aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis), molds (Cladosporium herbarum, Alternaria alternata, Aspergillus fumigatus, Penicillium notatum), cat and dog danders, Periplaneta americana, grass six mix, weed mix (Inmunotek, Spain) on 80 patients (18 to 50 years old) seen in our allergy center, they suffering from november to january rhinitis and/or conjunctivitis symptoms. The majority living near avenues and large green areas, where Tipuana trees grew.

Results: We found a total of 952 grains/m³ of Tipuana tipu pollen between November 2020 to january 2021, with the maximum concentration of 37 grains/m³ on December 10^th. We also found other airborne pollen Types: Poaceae, Myrtaceae, Compositae and Betulaceae. 14/80 patients (17,5%) showed positive skin prick test only to Tipuana tipu extract. Most of the patients with positive tests to Tipuana extract presented symptoms of rhinoconjunctivitis during the Tipuana pollination period. Four patients showed positive skin prick test to Tipuana tipu and grass 6 mix extracts, most of the rest of our patients were sensitized to dust mites' extracts (Dermatophagoides pteronyssinus).

Conclusions: The west-south population of Lima urban city is exposed to Tipuana tipu pollen. We do not foud previous publications about Tipuana tipu allergy. Almost 18% of the patients tested in our sample were mono-sensitized to this pollen. The results of this study should be compared with data from the forthcoming years, to identify seasonal and annual fluctuations, extend the traps to other locations in Lima, and of course try to standardize and improve the Tipuana tipu pollen extract.